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abundant Angistorhinus Animikie Archean asthenosphere augite basin beds Berry Black Hand bowlders Bull Cambrian Caraca quartzite clay coal coarse conglomerate correlation County Creek Cretaceous crystals Cuyahoga deposits depth diabase dikes district drift east eastern Eocene epoch erosion evidence facies fauna feet feldspar flora folding fossils fragments glacial glaciers gneiss gorge granite greenstone Heer Hollick Huronian igneous rocks inclusions intrusive iron formation Jour Keewatin Keweenawan Lake Superior Laurentian lavas Lesquereux leucite Lignite limestone lower material metamorphism miles Minas Geraes minerals Mines moraines mountain Mystriosuchus Negaunee Newberry occur origin outcrops Paleozoic pebbles peneplain portion posterior pre-Cambrian present pressure probably quartz quartzite Range region sand sandstone schist sedimentary sediments shale shown slate species strata stratigraphic stream structure surface temperature Tertiary thickness thin tion U.S. Geol U.S. Geological Survey unconformity Upper Huronian valley western width Wind River
Page 479 - A geologic reconnaissance of the Fairbanks quadrangle, Alaska, by LM Prindle, with a detailed description of the Fairbanks district, by LM Prindle and FJ Katz, and an account of lode mining near Fairbanks, by PS Smith. Bulletin 525, 1913, 220 pp. The Koyukuk-Chandalar region, Alaska, by AG Maddren. Bulletin 532, 1913, 119 pp. Price, 25 cents. A geologic reconnaissance of the Circle quadrangle, Alaska, by LM Prindle.
Page 598 - Porcupine and at many other localities, and of auriferous mispickel. Deposits of galena, zinc blende, fluorite, and other minerals also appear to have been derived from the granites, but some of them were not formed till post pre-Cambrian time. Preceding the intrusion of the Algoman granites, basic intrusives, that appear to be of post-Timiskamian age, gave rise to nickel and titaniferous and non-titaniferous magnetite deposits and chromite. TIMISKAMIAN Epoch of minor deposition of "iron formation
Page 591 - It there breaks through and disturbs the gneiss of the Laurentian series, and forms a nucleus from which emanates a complexity of dykes, proceeding to considerable distances. As dykes of a similar character are met with intersecting the rocks of the Huronian series, the nucleus in question is supposed to be of the Huronian age, as well as the greenstone dykes which are intersected by it.
Page 599 - ... represented in the table, nothing being received for them by the mines. A comparatively small quantity of the nickel and copper in the table should be credited to the deposit in Dundonald township that is associated with the basic eruptives of pre-Algoman and probably post-Timiskamian age. It should be understood that the ages given for the deposits do not refer to secondary concentration, as, for instance, in the case of iron ores, but to the epoch In which the metals were first deposited. Metal...
Page 583 - Mineral deposits of the Cerbat Range, Black Mountains, and Grand Wash Cliffs, Mohave County, Arizona: US Geol.
Page ii - THE CAMBRIDGE UNIVERSITY PRESS LONDON AND EDINBURGH THE MARUZEN-KABUSHIKI-KAISHA TOKYO, OSAKA, KYOTO KARL W. HIERSEMANN LEIPZIG THE BAKER & TAYLOR COMPANY NEW...
Page 496 - Among the corals collected here, Dr. TW Vaughan determined Favosites ( ?) polygonalis Duncan, Goniastrea antiguensis Duncan, Acropora (?), sp., Orbicella, n. sp., and Goniopora, sp., very similar to or identical with an Antiguan species. These, he says, indicate an Upper Oligocene horizon about equivalent to the Chattahoochee of Georgia. Around the San Jose de las Rusias Ranch the beds which are exposed show considerable disturbance. Immediately at the ranch the beds, which are fossiliferous sandstones,...
Page 533 - The marine member is composed predominantly of dark sandy shale or shaly sandstone with a subordinate amount of darkyellow and gray sandstone. It also contains some thin limestones. All the strata are lenticular in character and individual beds can be followed for only short distances.
Page 745 - Just as in the selective formation of what in my last memoir were described as salt-alloys we may have the artificial type of the genesis of many primary rocks and metamorphic modifications, so in the wonderful solubility in or miscibility with water of such alloys and of some salts at high temperatures we may have a no less clear type of the formation of certain volcanic rocks and an explanation of some of their peculiarities. The function of water in affecting rocks has been subjected to a most...